One execution was in Georgia and the other in Missouri. Both were also by lethal injection.
In the first of them, Marcus Wellons, 58, convicted of the 1989 kidnapping, rape and murder of a 15-year-old girl, was put to death shortly before midnight in the southern state of Georgia, a spokesman for the prison system said.
In the second case, John Winfield, 43, convicted of killing two women, was executed in the central state of Missouri, state prison system spokesman Mike O'Connell said.
A third execution was also scheduled for 6:00 pm (2200 GMT) today in the southern state of Florida.
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US states using the death penalty have faced crises over shortages of lethal injection drugs after European suppliers stopped supplying pentobarbital for use in executions.
The shortages have prompted prison departments in the 32 states that still allow the death penalty to seek new supply sources or new drug protocols.
In Oklahoma in April, Clayton Lockett, a convicted killer and rapist, was put to death by lethal injection in a process that took 43 minutes, well over the expected time of a little over 10 minutes.
Since then each execution slated to take place had been delayed as states reviewed their execution procedures.